365 resultados para Epidemics
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This research aims at finding out how scientific knowledge reached the common people in nineteenth century Portugal, using newspapers as the main source of information. Collecting news on science and technology is part of a larger research project focused on producing a History of the Popularization of Science and Technology in Portugal, following a model already developed in the UK and the USA (Bauer 2007). This source was probably the most widespread vehicle to divulge the latest scientific news at the time to an unspecialised audience. The following themes are approached: Drug advertisements in the nineteenth century. How did scientific knowledge on diseases and treatments reach the consumer? How did newspapers deal with epidemics? What were the prevention measures and the known treatments at the time? And what was the role of newspapers as educators? Ads show us the interest on divulging new products and the role of publicity as moulder of minds. All these questions introduce us to the role of the media on the subject of social perception of science and technology and the way scientific knowledge reached the common citizen.
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The authors report the clinical, laboratorial and epidemiological aspects of a human case of jungle yellow fever. The patient suffered from fever, chills, sweating, headaches, backaches, myalgia, epigastric pains, nausea, vomiting, diarrhea and prostration. He was unvaccinated and had been working in areas where cases of jungle yellow fever had been confirmed. Investigations concerning the yellow fever virus were performed. Blood samples were collected on several days in the course of the illness. Three of these samples (those obtained on days 5,7 and 10) were inoculated into suckling mice in attempt to isolate virus and to titrate the viremia level. Serological surveys were carried out by using the IgM Antibodies Capture Enzyme Linked Immunosorbent Assay (MAC-ELISA), Complement Fixation (CF), Hemagglulinalion Inhibition (HI) and Neutralization (N) tests. The yellow fever virus, recovered from the two first samples and the virus titration, showed high level of viremia. After that, specific antibodies appeared in all samples. The interval between the end of the viremia and the appearance of the antibodies was associated with the worsening of clinical symptoms, including bleeding of the mucous membrane. One must be aware of the risk of having a urban epidemics in areas where Aedes aegypti is found in high infestation indexes.
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A seroepidemiologic survey was carried out in schoolchildren from public schools of the Niterói municipality, state of Rio de Janeiro, Brazil, after a period of sequential epidemics by dengue virus type 1 and 2 (DEN-1 and DEN-2). 450 blood samples were obtained by fingertip puncture and collected on filter paper discs. The hemagglutination inhibition (HAI) test was carried out using DEN-1 and DEN-2 antigens. HAI titres were demonstrated in 66% (297/450) of the sera and the geometric means of the titres were 1/182 and 1/71 for DEN-1 and DEN-2, respectively. Secondary infections were observed in 61% (181/297) of positive cases. Among these, 75% (135/181) were under fifteen years old. No dengue haemorrhagic fever (DHF) was reported in these children. Asymptomatic or oligosymptomatic infections were detected in 56% of the studied population. The absolute and relative frequencies of positive tests by age group and sex did not evidence statistically significant difference. The number of individuals infected probably produced a immunologic barrier responsible for the non occurrence of dengue epidemic in the latter years.
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From 1950 to 1990 a total of 45,862 strains (31,517 isolates from human sources, and 14,345 of non-human origin) were identified at Instituto Adolfo Lutz. No prevalence of any serovars was seen during the period 1950-66 among human sources isolates. Important changing pattern was seen in 1968, when S. Typhimurim surprisingly increased becoming the prevalent serovar in the following decades. During the period of 1970-76, S. Typhimurium represented 77.7% of all serovars of human origin. Significant rise in S. Agona isolation as well as in the number of different serovars among human sources strains were seen in the late 70' and the 80's. More than one hundred different serovars were identified among non-human origin strains. Among serovars isolated from human sources, 74.9%, 15.5%, and 3.7% were recovered from stool, blood, and cerebrospinal fluid cultures, respectively. The outbreak of meningitis by S. Grumpensis in the 60's, emphasizes the concept that any Salmonella serovars can be a cause of epidemics, mainly of the nosocomial origin. This evaluation covering a long period shows the important role of the Public Health Laboratory in the surveillance of salmonellosis, one of the most frequent zoonosis in the world.
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We conducted a retrospective analysis of Toxoplasma encephalitis patients from Instituto de Infectologia Emílio Ribas, the main AIDS hospital of São Paulo, Brazil, during two different stages of the HIV epidemics, in 1988 (38 patients) and 1991 (33 patients). There were AIDS-related demographic differences, but the clinical presentation and diagnostic efficiency were similar, usually based on tomography and clinical response to therapy, with a clear distinction from other CNS infections, based on clinical and laboratory findings. Specific serologic studies were performed less often in 1991, with a high frequency of therapy change. The direct acute death rate from Toxoplasma encephalitis was high during both periods, i.e. 8/38 in 1988 and 10/33 in 1991. The direct acute death rate for the patients from the two periods as a whole was 25.4% (18/71), related to the time of HIV infection, absence of fever and presence of meningeal irritation at presentation, blood leukocytes higher than 10,000/mm³ and blood lymphocytes lower than 350/mm³. Toxoplasma encephalitis is a preventable disease when adequate prophylactic therapy is used and is relatively easy to treat in diagnosed HIV patients. Unfortunately, this severe and deadly disorder is the HIV diagnostic disease in several patients, and our data support the need for careful management of these patients, especially in those countries with a high toxoplasmosis prevalence where AIDS is concurrent with economic and public health problems.
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Dissertação para obtenção do Grau de Mestre em Matemática e Aplicações Especialização em Actuariado, Estatística e Investigação Operacional
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Cyanobacteria deteriorate the water quality and are responsible for emerging outbreaks and epidemics causing harmful diseases in Humans and animals because of their toxins. Microcystin-LR (MCT) is one of the most relevant cyanotoxin, being the most widely studied hepatotoxin. For safety purposes, the World Health Organization recommends a maximum value of 1 μg L−1 of MCT in drinking water. Therefore, there is a great demand for remote and real-time sensing techniques to detect and quantify MCT. In this work a Fabry–Pérot sensing probe based on an optical fibre tip coated with a MCT selective thin film is presented. The membranes were developed by imprinting MCT in a sol–gel matrix that was applied over the tip of the fibre by dip coating. The imprinting effect was obtained by curing the sol–gel membrane, prepared with (3-aminopropyl) trimethoxysilane (APTMS), diphenyl-dimethoxysilane (DPDMS), tetraethoxysilane (TEOS), in the presence of MCT. The imprinting effect was tested by preparing a similar membrane without template. In general, the fibre Fabry–Pérot with a Molecular Imprinted Polymer (MIP) sensor showed low thermal effect, thus avoiding the need of temperature control in field applications. It presented a linear response to MCT concentration within 0.3–1.4 μg L−1 with a sensitivity of −12.4 ± 0.7 nm L μg−1. The corresponding Non-Imprinted Polymer (NIP) displayed linear behaviour for the same MCT concentration range, but with much less sensitivity, of −5.9 ± 0.2 nm L μg−1. The method shows excellent selectivity for MCT against other species co-existing with the analyte in environmental waters. It was successfully applied to the determination of MCT in contaminated samples. The main advantages of the proposed optical sensor include high sensitivity and specificity, low-cost, robustness, easy preparation and preservation.
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In South Brazil the circulation of two HIV-1 subtypes with different characteristics represents an important scenario for the study of the impact of HIV-1 diversity on the evolution of the HIV-1 epidemic and AIDS disease. HIV-1 B, the predominant variant in industrialized countries and HIV-1 C, the most prevalent subtype in areas with rapid epidemic growth, are implicated in most infections. We evaluated blood samples from 128 antiretroviral (ARV) naïve patients recruited at entry to the largest HIV outpatient service in Porto Alegre. Based on partial pol region sequencing, HIV-1 C was observed in 29%, HIV-1 B in 22.6% and, the recently identified CRF31_BC, in 23.4% of 128 volunteers. Other variants were HIV-1 F in 10% and other mosaics in 5.5%. In order to evaluate the association of socio-behavioral characteristics and HIV-1 subtypes, interviews and laboratory evaluation were performed at entry. Our data suggest an established epidemic of the three major variants, without any evidence of partitioning in either of the subgroups analyzed. However, anal sex practices were associated with subtype B, which could indicate a greater transmissibility of non-B variants by vaginal intercourse. This study provides baseline information for epidemiologic surveillance of the changes of the molecular characteristics of HIV-1 epidemics in this region.
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Toxoplasmosis, a protozoan disease, causes severe disease in fetuses during pregnancy and deadly encephalitis in HIV patients. There are several studies on its seroprevalence around the world, but studies focusing on African countries are limited in number and mostly anecdotal. We studied two groups of samples from Mozambique by ELISA, using serum samples from 150 pregnant women and six Cerebrospinal fluid (CSF) samples from AIDS patients with encephalitis. HIV status was confirmed, and CD4 blood counts were obtained from HIV-positive pregnant women. IgG seroprevalence of the group as a whole was 18.7% (28/150), with a higher prevalence in HIV-positive individuals compared to those who were HIV-negative (31.3%, [18/58] vs. 10.9%, [10/92]) patients. These data may be biased due to cumulative effects of exposition affecting disease prevalence. If corrected, this data may indicate an interaction of HIV and T. gondii. Prevalence of both diseases increases with age, but this is more clearly seen for toxoplasmosis (p < 0.005) than HIV infection, possibly explained by higher transmission of HIV after childhood. In HIV patients suffering from encephalitis, CSF serology showed that 33% of specific IgG CSF had a high avidity, which was in accordance with the data from the group of pregnant women. Lower prevalence rates of both infections in older groups could be explained by more deaths in the infected groups, resulting in an artificially lower prevalence. Using CD4 counts as a marker of time of HIV infection, and correcting for age, patients with contact with T. gondii had fewer CD4 cells, suggesting prolonged HIV disease or other causes. Toxoplasma IgG prevalence is higher in HIV+ groups, which could be ascribed to HIV- and T. gondii-associated risk factors, such as exposure to higher and more diverse social contacts. The low incidence of Toxoplasma IgG in younger age groups shows that transmission could be related to better access to cyst-containing meat in adulthood, as environmental transmission due to oocysts is usually blamed for higher incidence in children. Taken together, these data support the urgent need of research in toxoplasmosis in Africa, especially in the presence of HIV epidemics.
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After detecting the death of Howlers monkeys (genus Alouatta) and isolation of yellow fever virus (YFV) in Buri county, São Paulo, Brazil, an entomological research study in the field was started. A YFV strain was isolated from newborn Swiss mice and cultured cells of Aedes albopictus - C6/36, from a pool of six Haemagogus (Conopostegus) leucocelaenus (Hg. leucocelaenus) mosquitoes (Dyar & Shannon) collected at the study site. Virus RNA fragment was amplified by RT-PCR and sequenced. The MCC Tree generated showed that the isolated strain is related to the South American I genotype, in a monophyletic clade containing isolates from recent 2008-2010 epidemics and epizootics in Brazil. Statistical analysis commonly used were calculated to characterize the sample in relation to diversity and dominance and indicated a pattern of dominance of one or a few species. Hg. leucocelaenus was found infected in Rio Grande do Sul State as well. In São Paulo State, this is the first detection of YFV in Hg. leucocelaenus.
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The dengue virus (DENV), which is frequently involved in large epidemics, and the yellow fever virus (YFV), which is responsible for sporadic sylvatic outbreaks, are considered the most important flaviviruses circulating in Brazil. Because of that, laboratorial diagnosis of acute undifferentiated febrile illness during epidemic periods is frequently directed towards these viruses, which may eventually hinder the detection of other circulating flaviviruses, including the Saint Louis encephalitis virus (SLEV), which is widely dispersed across the Americas. The aim of this study was to conduct a molecular investigation of 11 flaviviruses using 604 serum samples obtained from patients during a large dengue fever outbreak in the state of Mato Grosso (MT) between 2011 and 2012. Simultaneously, 3,433 female Culex spp. collected with Nasci aspirators in the city of Cuiabá, MT, in 2013, and allocated to 409 pools containing 1-10 mosquitoes, were also tested by multiplex semi-nested reverse transcription PCR for the same flaviviruses. SLEV was detected in three patients co-infected with DENV-4 from the cities of Cuiabá and Várzea Grande. One of them was a triple co-infection with DENV-1. None of them mentioned recent travel or access to sylvatic/rural regions, indicating that transmission might have occurred within the metropolitan area. Regarding mosquito samples, one pool containing one Culex quinquefasciatus female was positive for SLEV, with a minimum infection rate (MIR) of 0.29 per 1000 specimens of this species. Phylogenetic analysis indicates both human and mosquito SLEV cluster, with isolates from genotype V-A obtained from animals in the Amazon region, in the state of Pará. This is the first report of SLEV molecular identification in MT.
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RESUMO - A obesidade é um problema de saúde pública com dimensões alarmantes, motivo pelo qual foi classificada como uma das principais epidemias do século XXI. Estudos recentes demonstram que a prevalência da obesidade tem vindo a aumentar, sendo Portugal um dos países onde as taxas de prevalência são mais elevadas. No caso da obesidade infantil a situação também é muito preocupante. As crianças com excesso de peso ou obesas têm um risco acrescido de se tornarem adultos com doenças crónicas pelo que importa, desde cedo, desenvolver estratégias que permitam promover estilos de vida saudáveis e prevenir as várias doenças associadas. O desenvolvimento de intervenções durante a infância é considerado como uma das mais promissoras estratégias para a redução do excesso de peso e obesidade. Por outro lado, a escola é considerada como um dos locais mais atrativos e populares para se desenvolverem esses programas. Com este estudo pretendeu-se avaliar a intervenção realizada no concelho de Faro e verificar a sua efetividade no cumprimento dos objetivos definidos. A intervenção realizada em Faro, durante os anos letivos de 2007/2008 a 2010/2011, a 857 alunos do ensino básico, com idades compreendidas entre os 6 e os 10 anos de idade, teve como objetivos: avaliar e estabilizar a prevalência da obesidade infantil nas escolas do ensino básico do concelho de Faro, no ano letivo de 2007/2008; avaliar a evolução da prevalência da obesidade infantil durante os anos letivos de 2007/2008 a 2010/2011; e desenvolver estratégias para a promoção, em meio escolar, de uma alimentação mais saudável durante a intervenção. Os resultados levam-nos a concluir que a prevalência do excesso de peso e obesidade (15,2% e 10,5%, respetivamente) continua a níveis muito preocupantes nas crianças, tendo as raparigas apresentado uma prevalência maior do que os rapazes. A avaliação dos alunos, acompanhados prospetivamente ao longo dos primeiros 3 anos de intervenção, demonstrou uma diminuição da prevalência da obesidade de 9,6% no ano inicial para 8,3% no 3.º ano, e uma subida da taxa de prevalência do excesso de peso de 12,9% para 21,0%. A avaliação deste tipo de intervenções, apesar de difícil realização, é importante para que se possam definir novas estratégias, novas metodologias e novos caminhos para combater a obesidade infantil.
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RESUMO: O vírus chikungunya (CHIKV) é um vírus de RNA, com invólucro, da família Togaviridae, transmitido por mosquitos Aedes spp. Distribuído por largas regiões de África e Ásia, causa grandes epidemias de artrite grave. A semelhança de sintomas com outras doenças como a dengue e a malária e a persistência de IgM específicas, dificultam o diagnóstico da infeção por CHIKV. A deteção no sangue de E3, uma glicoproteína viral secretada, a incluir num ensaio imunoenzimático poderá melhorar o diagnóstico nos países onde as técnicas de biologia molecular são de difícil acesso. Para testar a utilidade de E3 num ensaio de diagnóstico, esta deverá ser expressa em quantidade, purificada e usada para produção de anticorpos específicos. Para expressar E3 numa forma solúvel, suscetível de ser purificada num único passo cromatográfico sem proteases, recorreu-se à estratégia da fusão com o domínio de ligação à quitina (CBD)-inteína (IMPACT™ System, NEB). A sequência codificadora de E3 foi amplificada a partir de RNA viral, clonada em pTYB21 e expressa em E. coli como uma proteína de fusão insolúvel de 64 kDa. A expressão a 12ºC induzida por IPTG 0,1 mM aumentou a solubilidade de CBD-inteína-E3. A aplicação de lisados celulares em colunas de quitina originou a retenção de CBD-inteína-E3 na matriz. Porém, a autoclivagem da inteína na coluna, induzida com reagentes tiol, foi pouco eficiente e mesmo a proteína E3 separada não eluiu da coluna. E3 foi ainda expressa em E. coli com uma cauda de seis histidinas (E3[His]6) por clonagem no vetor pET28b(+). Lisados celulares aplicados em colunas de níquel permitiram a eluição de uma proteína de 9 kDa, compatível com a massa molecular estimada para E3[His]6, ainda que com outros contaminantes proteicos. A identidade da proteína de 9 kDa será confirmada pela indução de anticorpos com esta preparação e reatividade daqueles com células infetadas com CHIKV.----------------ABSTRACT: Chikungunya virus (CHIKV) is an enveloped, positive strand RNA virus belonging to the family Togaviridae. Transmitted by Aedes spp mosquitoes, CHIKV causes large epidemics of severe arthritogenic disease in Africa and Asia and represents a serious threat in countries where vectors are present. Symptoms similarity with other diseases, e.g. dengue and malaria, along with CHIKV IgM persistence turns accurate CHIKV diagnosis a difficult task in low-income countries. Detection of E3, a small secreted viral glycoprotein, to be included in an immunoenzymatic test was envisaged as a possible improvement in CHIKV diagnosis. To test the diagnostic value of E3, recombinant E3 should be expressed and purified to generate antibodies. In order to express CHIKV E3 in a soluble form amenable to purification by a single step affinity chromatography, the chitin binding domain (CBD)-intein fusion strategy without proteases (IMPACT™ System, NEB) was employed. The E3 coding sequence was amplified from viral RNA, cloned in pTYB21 and expressed in E. coli ER2566 as an insoluble 64 kDa CBD-intein-E3 fusion protein. Solubility was partially achieved by lowering the expression temperature to 12ºC and the inducer (IPTG) concentration to 0.1 mM. Clarified cell lysate loaded onto a chitin column allowed ligation of the fusion protein but the intein-mediated cleavage efficiency was low and E3 failed to elute from the column as demonstrated by SDS-PAGE. E3 was further expressed with a six histidine tag, E3[His]6, employing the pET System (Novagen). E3[His]6 was expressed in E. coli Rosetta (30ºC, 0.4 mM IPTG) as a 9 kDa protein. Soluble cell extracts in 20-40 mM imidazole, applied onto a nickel column and eluted with 500 mM imidazole yielded a protein preparation enriched in the 9kDa protein. The 9 kDa will be used as antigen to generate antibodies that upon reaction with CHIKV infected cells will confirm its identity.
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Leptospirosis is a zoonotic disease that has emerged to cause epidemics in urban communities in developing countries. However, little is known about the infection in the general population. A seroprevalence survey was performed on a random sample of 1,390 subjects in Salvador, Brazil. Data on environmental and socioeconomic factors were collected. The microagglutination test of serum samples was used to show any prior Leptospira infection. The overall seroprevalence was 12.4%. Among the seropositive individuals, 111 (61%) had high titers for serovars of the Icterohaemorrhagiae serogroup. Seroprevalence increased with age and was similar for males and females. A positive correlation between Leptospira infection and low educational level was found. These findings indicate that a significant proportion of this urban population is exposed to pathogenic Leptospira. Public health actions for leptospirosis control will need to target not only the traditional groups at risk of infection with severe forms of this disease, but also the general population that is at risk.
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In Pernambuco, the first dengue cases occurred in 1987. After a seven-year interval without autochthonous cases, a new epidemic occurred in 1995. Important aspects of the dengue epidemics during the period 1995-2006 have been analyzed here, using epidemiological, clinical and laboratory data. A total of 378,374 cases were notified, with 612 confirmed cases of dengue hemorrhagic fever and 33 deaths. The mortality rate was 5.4%. The incidence rate increased from 134 to 1,438/100,000 inhabitants, corresponding to the epidemics due to serotypes 2 and 3, in 1995 and 2002, respectively. Dengue mainly affected adults (20-49 years); 40.7% were male and 59.3% were female. From 2003 onwards, the number of cases among individuals younger than 15 years old increased. Out of 225 dengue hemorrhagic fever cases, 42.7% primary and 57.3% secondary infections were identified (p = 0.0279). Neurological manifestations were also observed. From 2002 onwards, serotypes 1, 2 and 3 were circulating; serotype 3 was predominant.